Presets · Launcher · Docs

A preset is a ready set of settings for one pack: graphics, memory and Java, resource packs and shaders, sometimes configs and mods. The pack's author ships it, you read what exactly it will change before using it, apply it in one click and go back just as easily.

Using a preset

Open Presets in the instance detail. It lists presets from the pack's author and the built-in ones.

A preset shows a preview of the changes: which game options, how much memory and which Java, which resource packs and shaders, which config files and which mods.
Apply first backs up everything it touches (the last 3 backups are kept), then writes the changes. What takes effect only after a game restart, the card tells you beforehand. If the game is running, the preset is applied after it closes.
Revert puts back what the preset set and you have not changed since. What you edited yourself in the meantime stays, and the launcher tells you what it left. Added mods disappear, disabled ones come back on.

Controls (key bindings) are set by a preset only on request: a separate tick box, off by default.

Mods in a preset

A preset may add or disable mods, for example performance ones. Because a mod is executable code, stricter rules apply:

A mod is downloaded only from CurseForge or Modrinth by id and its checksum is verified against the portal, not against the preset.
A warning across the whole dialog says the preset adds N mods and that this is executable code, listing what and from where.
Conflicts (e.g. Sodium × OptiFine) and required dependencies are checked before applying. With a conflict the preset cannot be applied and the launcher says why.
Only a mod already in the pack can be disabled, and nothing is deleted.

Potato Mode

Potato Mode is, from 0.11, a built-in preset (stygion:potato) for weaker computers: a shorter render distance (6) and simulation distance (5), fast graphics, fewer particles, no clouds or shadows, 60 FPS. You apply and revert it like any other preset, with the preview and the backup.

Recommended for your PC

The Recommended for your PC button appears only where we have data from the measurements of similar machines, which is almost nowhere yet. No data, no guessing. How the data comes about: Performance and the benchmark.

Presets from players and online sharing do not exist yet. Presets from a pack's author and built-in ones work today.

For pack authors: how to ship a preset

A preset is a folder in the pack: config/stygion/presets/<id>/ with a preset.json file (and other files if needed). It goes into the pack's overrides like any config, so it travels with the pack from CurseForge and Modrinth. It does not need Keystone.

What preset.json may carry:

Part	What
`id`, `rev`, `name`, `sentence`	identity, revision, and a name with a sentence in Czech and English
`pack`	the pack, version, loader and Minecraft version it was made for
`options`	game options by key, merged into `options.txt`. Key bindings (`key_*`) only as a separate "Controls" group, off by default when applied
`jvm`	the choice `auto` / `g1` / `zgc` and a heap size; never custom arguments
`resources`	resource packs and shaders by link only to CurseForge/Modrinth, order and on/off
`mods`	mods to add by link only to a portal (project and file, hash from the portal) and pack mods to disable
`files`	whole config files (`config/`, `defaultconfigs/`), plain text formats only; the pack's author only

What it must never carry: .jar, .zip, .class files or scripts; kubejs/, scripts/ and saves/ folders; mods/ directly (only through mods); paths outside the instance (.., absolute paths, symlinks). The launcher checks these rules on every use.

A preset is tied to a pack version through pack.madeFor. When a new pack version changes files the preset overwrites, the launcher applies only the safe part and says so. Ship a new rev for the new version.